Jerry Trestman balanced himself with a black cane as he stood in the dimly lit concourse outside the Bears' locker room late Sunday afternoon. His navy hat with the orange "C" rested just above his glasses. He watched as his son doled out hugs and kisses to a dozen or so family members wearing blue and white jerseys. Cellphone cameras flashed. This was an occasion worth celebrating.

His son, Marc, coached the Bears to a 24-21 victory over the Bengals in his NFL debut. Better yet, the win required a thrilling comeback and a critical coaching decision in the fourth quarter.

Marc Trestman began his coaching career that year while studying law at the University of Miami. He took a few moments Sunday to appreciate his lengthy path to Soldier Field's home sideline.

In another way, though, it was only the beginning. A new chapter of Bears football started with some inspired offense in the second half. And the familiarly fierce defense matched that with three takeaways.

Trestman downplayed what the milestone meant to him and deflected credit for the Bears' second-half surge.

Like cornerback Charles Tillman, who had two interceptions, and cornerback Tim Jennings, who set up the winning drive by forcing Bengals receiver Mohamed Sanu to fumble at the Bears' 19-yard line.

The Bears began their comeback when they gained possession for the first time in the second half, trailing 21-10.

To that point, the offense lacked the rhythm and efficiency Trestman demands. Players sensed a change after halftime. But they didn't do anything differently. Instead, persistence lifted them.

"The whole game we knew we were in it," center Roberto Garza said. "You know our defense can create turnovers, so it was just a matter of us finding a rhythm, and we did that. We were able to run the football, and Jay had an incredible night standing in the pocket and throwing the ball to our playmakers."

Cutler usually had time to scan the field, and when he didn't, he extended plays with his feet. He converted both third-down passes he threw in the second half.

"We started clicking a little bit," he said. "We weren't really happy early on. Our tempo was a little off kilter. It was just a matter of us keep calling plays, be confident in what we were doing."

Trestman exuded such confidence with the outcome in the balance.

The Bears, trailing 21-17 with 8:32 remaining, faced fourth-and-inches from the Bengals' 27. They had two timeouts, so they could have attempted a field goal and relied on the defense to get the ball back. But Trestman kept his offense on the field.

"Ballsy play-calling," Cutler said. "That's what Trestman's about."

Matt Forte scampered 8 yards around the right edge. On the next play, Cutler exploited the Bengals' decision to cover Marshall with a single safety.

Marshall was the third read in Cutler's progression. Cutler's perfectly placed the throw at the left sideline in the end zone.

"I didn't understand it," Marshall said. "Fourth quarter, put a safety on me on one? You can only ask for that in dreams."

The Bears held the Bengals to a three-and-out on the ensuing drive and then ran out the final 6:38. Trestman clapped emphatically five times as the final seconds elapsed. He became only the fourth coach in franchise history to win his debut.

Maybe Marshall was on to something. It was a dream beginning.

After Trestman fulfilled his postgame media obligations, his family greeted him in the concourse with a round of cheers. Trestman kissed his wife, Cindy, who then stood back from the celebration. "Unbelievable," she muttered to no one in particular as tears welled in her eyes.

Trestman posed for pictures and relished the moment. He shared 10 minutes or so with them before disappearing back into to the locker room to continue the day's work.